Photoresist layer surface treatment, cap layer, and method of forming photoresist pattern

ABSTRACT

A method of forming a pattern in a photoresist layer includes forming a photoresist layer over a substrate, and reducing moisture or oxygen absorption characteristics of the photoresist layer. The photoresist layer is selectively exposed to actinic radiation to form a latent pattern, and the latent pattern is developed by applying a developer to the selectively exposed photoresist layer to form a pattern.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationNo. 63/002,297 filed Mar. 30, 2020, and U.S. Provisional PatentApplication No. 63/026,695 filed May 18, 2020, the entire contents ofeach are incorporated herein by reference.

BACKGROUND

As consumer devices have gotten smaller and smaller in response toconsumer demand, the individual components of these devices havenecessarily decreased in size as well. Semiconductor devices, which makeup a major component of devices such as mobile phones, computer tablets,and the like, have been pressured to become smaller and smaller, with acorresponding pressure on the individual devices (e.g., transistors,resistors, capacitors, etc.) within the semiconductor devices to also bereduced in size.

One enabling technology that is used in the manufacturing processes ofsemiconductor devices is the use of photolithographic materials. Suchmaterials are applied to a surface of a layer to be patterned and thenexposed to an energy that has itself been patterned. Such an exposuremodifies the chemical and physical properties of the exposed regions ofthe photosensitive material. This modification, along with the lack ofmodification in regions of the photosensitive material that were notexposed, can be exploited to remove one region without removing theother.

However, as the size of individual devices has decreased, processwindows for photolithographic processing has become tighter and tighter.As such, advances in the field of photolithographic processing arenecessary to maintain the ability to scale down the devices, and furtherimprovements are needed in order to meet the desired design criteriasuch that the march towards smaller and smaller components may bemaintained.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is best understood from the following detaileddescription when read with the accompanying figures. It is emphasizedthat, in accordance with the standard practice in the industry, variousfeatures are not drawn to scale and are used for illustration purposesonly. In fact, the dimensions of the various features may be arbitrarilyincreased or reduced for clarity of discussion.

FIG. 1 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIGS. 2A and 2B illustrate process flows of manufacturing asemiconductor device according to embodiments of the disclosure.

FIG. 3 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIGS. 4A and 4B show a process stage of a sequential operation accordingto embodiments of the disclosure.

FIGS. 5A, 5B, 5C, and 5D show a process stage of a sequential operationaccording to embodiments of the disclosure.

FIGS. 6A, 6B, 6C, 6D, 6E, and 6F show a process stage of a sequentialoperation according to embodiments of the disclosure.

FIG. 7 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 8 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIGS. 9A, 9B, and 9C show organometallic precursors according toembodiments of the disclosure.

FIG. 10 shows a photoresist deposition apparatus according to someembodiments of the disclosure.

FIG. 11 shows a reaction the photoresist layer undergoes as a result ofexposure to actinic radiation and heating according to an embodiment ofthe disclosure.

FIG. 12A shows a surface treatment operation according to an embodimentof the disclosure.

FIG. 12B shows a cap layer formation operation according to anembodiment of the disclosure.

FIG. 13 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIGS. 14A and 14B show a process stage of a sequential operationaccording to embodiments of the disclosure.

FIGS. 15A, 15B, 15C, and 15D show a process stage of a sequentialoperation according to embodiments of the disclosure.

FIGS. 16A, 16B, 16C, 16D, 16E, and 16F show a process stage of asequential operation according to embodiments of the disclosure.

FIG. 17 shows a process stage of a sequential operation according to anembodiment of the disclosure.

FIG. 18 shows a process stage of a sequential operation according to anembodiment of the disclosure.

DETAILED DESCRIPTION

It is to be understood that the following disclosure provides manydifferent embodiments, or examples, for implementing different featuresof the disclosure. Specific embodiments or examples of components andarrangements are described below to simplify the present disclosure.These are, of course, merely examples and are not intended to belimiting. For example, dimensions of elements are not limited to thedisclosed range or values, but may depend upon process conditions and/ordesired properties of the device. Moreover, the formation of a firstfeature over or on a second feature in the description that follows mayinclude embodiments in which the first and second features are formed indirect contact, and may also include embodiments in which additionalfeatures may be formed interposing the first and second features, suchthat the first and second features may not be in direct contact. Variousfeatures may be arbitrarily drawn in different scales for simplicity andclarity.

Further, spatially relative terms, such as “beneath,” “below,” “lower,”“above,” “upper” and the like, may be used herein for ease ofdescription to describe one element or feature's relationship to anotherelement(s) or feature(s) as illustrated in the figures. The spatiallyrelative terms are intended to encompass different orientations of thedevice in use or operation in addition to the orientation depicted inthe figures. The device may be otherwise oriented (rotated 90 degrees orat other orientations) and the spatially relative descriptors usedherein may likewise be interpreted accordingly. In addition, the term“made of” may mean either “comprising” or “consisting of.”

As the semiconductor industry has progressed into nanometer technologyprocess nodes in pursuit of higher device density, higher performance,and lower costs, there have been challenges in reducing semiconductorfeature size. Extreme ultraviolet lithography (EUVL) has been developedto form smaller semiconductor device feature size and increase devicedensity on a semiconductor wafer. In order to improve EUVL, an increasein wafer exposure throughput is desirable. Wafer exposure throughput canbe improved through increased exposure power or increased resistphotospeed (sensitivity).

Metal-containing photoresists are used in extreme ultravioletlithography because metals have a high absorption capacity of EUVradiation. Metal-containing photoresists, however, absorb ambientmoisture and oxygen, which can degrade the pattern resolution. Theabsorption of moisture and oxygen may initiate the crosslinking reactionin the photoresist layer thereby decreasing the solubility of thenon-exposed regions in the photoresist to the photoresist developer. Inaddition, volatile precursors in the photoresist layer may outgas priorto the radiation exposure and development operations, which would causethe photoresist layer quality to change over time, and may causecontamination to the semiconductor device processing chamber, handlingequipment, and other semiconductor wafers. The photoresist layermoisture and oxygen absorption and photoresist outgassing negativelyaffects the lithography performance and increases defects.

To prevent moisture and oxygen absorption and photoresist outgassing,embodiments of the disclosure treat the surface of the photoresist layeror form a cap layer over the photoresist layer, as shown in FIG. 1.Surface treatment operations according to the present disclosure includemodifying ligands in the metal-containing photoresist to converthydrophilic end groups on the surface of the ligands in the photoresistlayer to hydrophobic end groups.

In some embodiments, hydrophilic ligand end groups at the upper surfaceof the photo resist layer are replaced with hydrophobic end groups. Insome embodiments, the photoresist layer is treated with a plasma orundergoes a thermal treatment to change the hydrophilic ligand endgroups to hydrophobic end groups.

In other embodiments, a cap layer is deposited on the photoresist layer,as shown in FIG. 1. In some embodiments, the cap layer is a monolayer.In some embodiments, the cap layer is a dielectric layer.

The surface treatment and cap layer protect the photoresist layer fromexposure to ambient moisture and oxygen, and inhibits outgassing,thereby stabilizing the photoresist layer and reducing defects. Thesurface treatment and cap layer improve developer dispersion on thephotoresist surface thereby reducing scum and bridge defects.

FIGS. 2A and 2B illustrate process flows 100 of manufacturing asemiconductor device according to embodiments of the disclosure. Aresist is coated on a surface of a layer to be patterned or a substrate10 in operation S110, in some embodiments, to form a resist layer 15, asshown in FIG. 3. In some embodiments, the resist is a metal-containingphotoresist formed by chemical vapor deposition (CVD) or atomic layerdeposition (ALD). In other embodiments, the metal-containing photoresistlayer is formed by a spin-coating method. In some embodiments, a surfacetreatment S115 is performed on the resist layer 15 to form a surfacetreated layer 20 a, as shown in FIGS. 2A and 4A. The surface treatmentS115 changes the surface of the resist layer 15 from a hydrophilicsurface to a hydrophobic surface.

In some embodiments, the resist layer 15 undergoes a first heatingoperation S120 after the surface treatment operation S115. In someembodiments, the first heating operation S120 includes heating theresist layer 15 at a temperature of between about 40° C. and about 150°C. for about 10 seconds to about 10 minutes during the first heatingoperation S120. In some embodiments, the resist layer 15 undergoes thefirst heating operation S120 before the surface treatment S115 isperformed on the resist layer 15.

In some embodiments, as shown in FIGS. 2B and 4B, a cap layer 20 b isformed in operation S125 over the resist layer 15. In some embodiments,the cap layer 20 b is formed before a first heating operation S120. Inother embodiments, the cap layer formation operation S125 is performedafter the first heating operation S120. In some embodiments, the resistlayer 15 is heated at a temperature of between about 40° C. and about150° C. for about 10 seconds to about 10 minutes during the firstheating operation S120.

The resist layer 15 and the surface treated layer 20 a or the resistlayer 15 and the cap layer 20 b are subsequently selectively exposed toactinic radiation 45/97 (see FIGS. 5A, 5B, 5C, and 5D) in operation S130of FIGS. 2A and 2B. The resist layer 15 is exposed to actinic radiation45/97 through the surface treated layer 20 a or cap layer 20 b. In someembodiments, the actinic radiation 45/97 is not substantially absorbedby the surface treated layer 20 a or cap layer 20 b. In someembodiments, the photoresist layer 15 is selectively or patternwiseexposed to ultraviolet radiation. In some embodiments, the ultravioletradiation is deep ultraviolet radiation (DUV). In some embodiments, theultraviolet radiation is extreme ultraviolet (EUV) radiation. In someembodiments, the resist layer 15 is selectively or patternwise exposedto an electron beam. In some embodiments, the resist layer 15 is aphotoresist layer that is photosensitive to the actinic radiation 45/97and the cap layer 20 b is not a photoresist layer and is notphotosensitive to the actinic radiation 45/97.

Photoresist layers according to the present disclosure are layers thatundergo a chemical reaction upon absorption of the actinic radiationcausing portions of the photoresist layer that are exposed to theactinic radiation to change solubility in a developer in contrast toportions of the photoresist layer that are not exposed to the actinicradiation. The layers that are not photosensitive to the actinicradiation do not substantially undergo a chemical reaction to change thelayer's solubility in a developer upon exposure to the actinicradiation.

As shown in FIGS. 5A and 5B, the exposure radiation 45 passes through aphotomask 30 before irradiating the photoresist layer 15 in someembodiments. In some embodiments, the photomask 30 has a pattern to bereplicated in the photoresist layer 15. The pattern is formed by anopaque pattern 35 on the photomask substrate 40, in some embodiments.The opaque pattern 35 may be formed by a material opaque to ultravioletradiation, such as chromium, while the photomask substrate 40 is formedof a material that is transparent to ultraviolet radiation, such asfused quartz.

In some embodiments, the selective or patternwise exposure of thephotoresist layer 15 to form exposed regions 50 and unexposed regions 52is performed using extreme ultraviolet lithography. In an extremeultraviolet lithography operation, a reflective photomask 65 is used toform the patterned exposure light in some embodiments, as shown in FIGS.5C and 5D. The reflective photomask 65 includes a low thermal expansionglass substrate 70, on which a reflective multilayer 75 of Si and Mo isformed. A capping layer 80 and absorber layer 85 are formed on thereflective multilayer 75. A rear conductive layer 90 is formed on theback side of the low thermal expansion substrate 70. Extreme ultravioletradiation 95 is directed towards the reflective photomask 65 at anincident angle of about 6°. A portion 97 of the extreme ultravioletradiation is reflected by the Si/Mo multilayer 75 towards thephotoresist-coated substrate 10, while the portion of the extremeultraviolet radiation incident upon the absorber layer 85 is absorbed bythe photomask. In some embodiments, additional optics, includingmirrors, are located between the reflective photomask 65 and thephotoresist-coated substrate 10.

In some embodiments, the exposure to radiation is carried out by placingthe photoresist-coated substrate in a photolithography tool. Thephotolithography tool includes a photomask 30/65, optics, an exposureradiation source to provide the radiation 45/97 for exposure, and amovable stage for supporting and moving the substrate under the exposureradiation.

In some embodiments, optics (not shown) are used in the photolithographytool to expand, reflect, or otherwise control the radiation before orafter the radiation 45/97 is patterned by the photomask 30/65. In someembodiments, the optics include one or more lenses, mirrors, filters,and combinations thereof to control the radiation 45/97 along its path.

In some embodiments, the radiation is electromagnetic radiation, such asg-line (wavelength of about 436 nm), i-line (wavelength of about 365nm), ultraviolet radiation, far ultraviolet radiation, extremeultraviolet, electron beams, or the like. In some embodiments, theradiation source is selected from the group consisting of a mercuryvapor lamp, xenon lamp, carbon arc lamp, a KrF excimer laser light(wavelength of 248 nm), an ArF excimer laser light (wavelength of 193nm), an F₂ excimer laser light (wavelength of 157 nm), or a CO₂laser-excited Sn plasma (extreme ultraviolet, wavelength of 13.5 nm).

The amount of electromagnetic radiation can be characterized by afluence or dose, which is obtained by the integrated radiative flux overthe exposure time. Suitable radiation fluences range from about 1 mJ/cm²to about 150 mJ/cm² in some embodiments, from about 2 mJ/cm² to about100 mJ/cm² in other embodiments, and from about 3 mJ/cm² to about 50mJ/cm² in other embodiments. A person of ordinary skill in the art willrecognize that additional ranges of radiation fluences within theexplicit ranges above are contemplated and are within the presentdisclosure.

In some embodiments, the selective or patternwise exposure is performedby a scanning electron beam. With electron beam lithography, theelectron beam induces secondary electrons, which modify the irradiatedmaterial. High resolution is achievable using electron beam lithographyand the metal-containing resists disclosed herein. Electron beams can becharacterized by the energy of the beam, and suitable energies rangefrom about 5 V to about 200 kV (kilovolt) in some embodiments, and fromabout 7.5 V to about 100 kV in other embodiments. Proximity-correctedbeam doses at 30 kV range from about 0.1 μC/cm² to about 5 μC/cm² insome embodiments, from about 0.5 μC/cm² to about 1 μC/cm² in otherembodiments, and in other embodiments from about 1 μC/cm² to about 100μC/cm². A person of ordinary skill in the art can compute correspondingdoses at other beam energies based on the teachings herein and willrecognize that additional ranges of electron beam properties within theexplicit ranges above are contemplated and are within the presentdisclosure.

In some embodiments, the exposure of the resist layer 15 uses animmersion lithography technique. In such a technique, an immersionmedium (not shown) is placed between the final optics and thephotoresist layer, and the exposure radiation 45 passes through theimmersion medium.

The region of the resist layer exposed to radiation 50 undergoes achemical reaction thereby changing its susceptibility to being removedin a subsequent development operation S150. In some embodiments, theportion of the resist layer exposed to radiation 50 undergoes a reactionmaking the exposed portion more easily removed during the developmentoperation S150. In other embodiments, the portion of the resist layerexposed to radiation 50 undergoes a reaction making the exposed portionresistant to removal during the development operation S150.

Next, the resist layer 15 undergoes a second heating or a post-exposurebake (PEB) in operation S140. In some embodiments, the resist layer 15is heated at a temperature of about 50° C. to about 250° C. for about 20seconds to about 300 seconds. In some embodiments, the post-exposurebaking is performed at a temperature ranging from about 100° C. to about230° C., and at a temperature ranging from about 150° C. to about 200°C. in other embodiments. In some embodiments, the post-exposure bakingoperation S140 causes the reaction product of a first compound or firstprecursor and a second compound or second precursor in the resist layerto crosslink.

The selectively exposed resist layer 15 is subsequently developed inoperation S150. In some embodiments, the resist layer 15 is developed byapplying a solvent-based developer 57 to the selectively exposed resistlayer. As shown in FIGS. 6A and 6B, a liquid developer 57 is suppliedfrom a dispenser 62 to the resist layer 15 and the surface treated layer20 a or the resist layer 15 and the cap layer 20 b, respectively. Insome embodiments, the exposed portions 50 of the photoresist undergo acrosslinking reaction as a result of the exposure to actinic radiationor the post-exposure bake, and the unexposed portion of the photoresistlayer 52 is removed by the developer 57 forming a pattern of openings 55in the photoresist layer 15 to expose the substrate 10, as shown in FIG.7. In some embodiments, the surface treated layer 20 a and cap layer 20b are removed during the development operation.

In some embodiments, the resist developer 57 includes a solvent, and anacid or a base. In some embodiments, the concentration of the solvent isfrom about 60 wt. % to about 99 wt. % based on the total weight of theresist developer. The acid or base concentration is from about 0.001 wt.% to about 20 wt. % based on the total weight of the resist developer.In certain embodiments, the acid or base concentration in the developeris from about 0.01 wt. % to about 15 wt. % based on the total weight ofthe resist developer.

In some embodiments, the developer 57 is applied to the resist layer 15using a spin-on process. In the spin-on process, the developer 57 isapplied to the resist layer 15 from above the resist layer 15 while theresist-coated substrate is rotated, as shown in FIG. 6A. In someembodiments, the developer 57 is supplied at a rate of between about 5ml/min and about 800 ml/min, while the photoresist coated substrate 10is rotated at a speed of between about 100 rpm and about 2000 rpm. Insome embodiments, the developer is at a temperature of between about 10°C. and about 80° C. The development operation continues for betweenabout 30 seconds to about 10 minutes in some embodiments.

In some embodiments, the developer 57 is an organic solvent. The organicsolvent can be any suitable solvent. In some embodiments, the solvent isone or more selected from propylene glycol methyl ether acetate (PGMEA),propylene glycol monomethyl ether (PGME), 1-ethoxy-2-propanol (PGEE),γ-butyrolactone (GBL), cyclohexanone (CHN), ethyl lactate (EL),methanol, ethanol, propanol, n-butanol, 4-methyl-2-pentanol, acetone,methyl ethyl ketone, dimethylformamide (DMF), isopropanol (IPA),tetrahydrofuran (THF), methyl isobutyl carbinol (MIBC), n-butyl acetate(nBA), 2-heptanone (MAK), tetrahydrofuran (THF), and dioxane.

While the spin-on operation is one suitable method for developing thephotoresist layer 15 after exposure, it is intended to be illustrativeand is not intended to limit the embodiment. Rather, any suitabledevelopment operations, including dip processes, puddle processes, andspray-on methods, may alternatively be used. All such developmentoperations are included within the scope of the embodiments.

In some embodiments, a dry developer 105 is applied to the selectivelyexposed resist layer 15 and the surface treated layer 20 a or cap layer20 b, as shown in FIGS. 6C and 6D. In some embodiments, the drydeveloper 105 is a plasma or chemical vapor, and the dry developmentoperation S150 is a plasma etching or chemical etching operation. Thedry development uses the differences related to the composition, extentof cross-linking, and film density to selectively remove the desiredportions of the resist. In some embodiments, the dry developmentprocesses uses either a gentle plasma (high pressure, low power) or athermal process in a heated vacuum chamber while flowing a drydevelopment chemistry, such as BCl₃, BF₃, or other Lewis Acid in thevapor state. In some embodiments, the BCl₃ removes the unexposedmaterial, leaving behind a pattern of the exposed film that istransferred into the underlying layers by plasma-based etch processes.

In some embodiments, the dry development includes plasma processes,including transformer coupled plasma (TCP), inductively coupled plasma(ICP) or capacitively coupled plasma (CCP). In some embodiments, theplasma process is conducted at a pressure of ranging from about 5 mTorrto a pressure of about 20 mTorr, at a power level from about 250 W toabout 1000 W, temperature ranging from about 0° C. to about 300° C., andat flow rate of about 100 to about 1000 sccm, for about 1 to about 3000seconds.

In some embodiments, the surface treated layer 20 a or cap layer 20 b isremoved after the post exposure bake operation S140 and before thedevelopment operation S150; and then subsequently developed by either awet development operation, as shown in FIG. 6E or dry developmentoperation, as shown in FIG. 6F. In some embodiments, the surface treatedlayer 20 a or cap layer 20 b is removed by a suitable solvent or by asuitable dry etchant.

The development operation S150 provides a pattern 55 in the photoresistlayer exposing portions of the substrate 10, as shown in FIG. 7. Afterthe development operation, additional processing is performed while thepatterned photoresist layer 15, 50 is in place. For example, an etchingoperation, using dry or wet etching, is performed in some embodiments,to transfer the pattern of the resist layer 15, 50 to the underlyingsubstrate 10, forming recesses 55′ as shown in FIG. 8. The substrate 10has a different etch resistance than the resist layer 15. In someembodiments, the etchant is more selective to the substrate 10 than theresist layer 15. In some embodiments, the patterned resist layer 15, 50is at least partially removed during the etching operation in someembodiments. In other embodiments, the patterned resist layer 15, 50 isremoved after etching the substrate 10 by selective etching, using asuitable resist stripper solvent, or by a resist plasma ashingoperation.

In some embodiments, the substrate 10 includes a single crystallinesemiconductor layer on at least it surface portion. The substrate 10 mayinclude a single crystalline semiconductor material such as, but notlimited to Si, Ge, SiGe, GaAs, InSb, GaP, GaSb, InAlAs, InGaAs, GaSbP,GaAsSb and InP. In some embodiments, the substrate 10 is a silicon layerof an SOI (silicon-on insulator) substrate. In certain embodiments, thesubstrate 10 is made of crystalline Si.

The substrate 10 may include in its surface region, one or more bufferlayers (not shown). The buffer layers can serve to gradually change thelattice constant from that of the substrate to that of subsequentlyformed source/drain regions. The buffer layers may be formed fromepitaxially grown single crystalline semiconductor materials such as,but not limited to Si, Ge, GeSn, SiGe, GaAs, InSb, GaP, GaSb, InAlAs,InGaAs, GaSbP, GaAsSb, GaN, GaP, and InP. In an embodiment, the silicongermanium (SiGe) buffer layer is epitaxially grown on the siliconsubstrate 10. The germanium concentration of the SiGe buffer layers mayincrease from 30 atomic % for the bottom-most buffer layer to 70 atomic% for the top-most buffer layer.

In some embodiments, the substrate 10 includes one or more layers of atleast one metal, metal alloy, and metal-nitride/sulfide/oxide/silicidehaving the formula MX_(a), where M is a metal and X is N, S, Se, 0, Si,and a is from about 0.4 to about 2.5. In some embodiments, the substrate10 includes titanium, aluminum, cobalt, ruthenium, titanium nitride,tungsten nitride, tantalum nitride, and combinations thereof.

In some embodiments, the substrate 10 includes a dielectric materialhaving at least a silicon or metal oxide or nitride of the formulaMX_(b), where M is a metal or Si, X is N or O, and b ranges from about0.4 to about 2.5. In some embodiments, the substrate 10 includes silicondioxide, silicon nitride, aluminum oxide, hafnium oxide, lanthanumoxide, and combinations thereof.

The photoresist layer 15 is a photosensitive layer that is patterned byexposure to actinic radiation. Typically, the chemical properties of thephotoresist regions struck by incident radiation change in a manner thatdepends on the type of photoresist used. Photoresist layers 15 areeither positive tone resists or negative tone resists. A positive toneresist refers to a photoresist material that when exposed to radiation,such as UV light, becomes soluble in a developer, while the region ofthe photoresist that is non-exposed (or exposed less) is insoluble inthe developer. A negative tone resist, on the other hand, refers to aphotoresist material that when exposed to radiation becomes insoluble inthe developer, while the region of the photoresist that is non-exposed(or exposed less) is soluble in the developer. The region of a negativeresist that becomes insoluble upon exposure to radiation may becomeinsoluble due to a cross-linking reaction caused by the exposure toradiation.

In some embodiments, the photoresist layer includes a high sensitivityphotoresist composition. In some embodiments, the high sensitivityphotoresist composition is highly sensitive to extreme ultraviolet (EUV)radiation.

In some embodiments, the photoresist layer 15 is made of a photoresistcomposition, including a first compound or a first precursor and asecond compound or a second precursor combined in a vapor state. Thefirst precursor or first compound is an organometallic having a formula:M_(a)R_(b)X_(c), as shown in FIG. 9A, where M is at least one of Sn, Bi,Sb, In, Te, Ti, Zr, Hf, V, Co, Mo, W, Al, Ga, Si, Ge, P, As, Y, La, Ce,or Lu; and R is a substituted or unsubstituted alkyl, alkenyl, orcarboxylate group. In some embodiments, M is selected from the groupconsisting of Sn, Bi, Sb, In, Te, and combinations thereof. In someembodiments, R is a C3-C6 alkyl, alkenyl, or carboxylate. In someembodiments, R is selected from the group consisting of propyl,isopropyl, butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, isopentyl,sec-pentyl, tert-pentyl, hexyl, iso-hexyl, sec-hexyl, tert-hexyl, andcombinations thereof. X is a ligand, ion, or other moiety, which isreactive with the second compound or second precursor; and 1≤a≤2, b≥1,c≥1, and b+c≤5 in some embodiments. In some embodiments, the alkyl,alkenyl, or carboxylate group is substituted with one or more fluorogroups. In some embodiments, the organometallic precursor is a dimer, asshown in FIG. 9A, where each monomer unit is linked by an amine group.Each monomer has a formula: M_(a)R_(b)X_(c), as defined above.

In some embodiments, R is alkyl, such as C_(n)H_(2n+1) where n≥3. Insome embodiments, R is fluorinated, e.g., having the formulaC_(n)F_(x)H_(((2n+1)-x)). In some embodiments, R has at least onebeta-hydrogen or beta-fluorine. In some embodiments, R is selected fromthe group consisting of i-propyl, n-propyl, t-butyl, i-butyl, n-butyl,sec-butyl, n-pentyl, i-pentyl, t-pentyl, and sec-pentyl, andcombinations thereof.

In some embodiments, X is any moiety readily displaced by the secondcompound or second precursor to generate an M-OH moiety, such as amoiety selected from the group consisting of amines, includingdialkylamino and monalkylamino; alkoxy; carboxylates, halogens, andsulfonates. In some embodiments, the sulfonate group is substituted withone or more amine groups. In some embodiments, the halide is one or moreselected from the group consisting of F, Cl, Br, and I. In someembodiments, the sulfonate group includes a substituted or unsubstitutedC1-C3 group.

In some embodiments, the first organometallic compound or firstorganometallic precursor includes a metallic core W with ligands Lattached to the metallic core M⁺, as shown in FIG. 9B. In someembodiments, the metallic core M⁺ is a metal oxide. The ligands Linclude C3-C12 aliphatic or aromatic groups in some embodiments. Thealiphatic or aromatic groups may be unbranched or branched with cyclic,or noncyclic saturated pendant groups containing 1-9 carbons, includingalkyl groups, alkenyl groups, and phenyl groups. The branched groups maybe further substituted with oxygen or halogen. In some embodiments, theC3-C12 aliphatic or aromatic groups include heterocyclic groups. In someembodiments, the C3-C12 aliphatic or aromatic groups are attached to themetal by an ether or ester linkage. In some embodiments, the C3-C12aliphatic or aromatic groups include nitrite and sulfonate substituents.

In some embodiments, the organometallic precursor or organometalliccompound include a sec-hexyl tris(dimethylamino) tin, t-hexyltris(dimethylamino) tin, i-hexyl tris(dimethylamino) tin, n-hexyltris(dimethylamino) tin, sec-pentyl tris(dimethylamino) tin, t-pentyltris(dimethylamino) tin, i-pentyl tris(dimethylamino) tin, n-pentyltris(dimethylamino) tin, sec-butyl tris(dimethylamino) tin, t-butyltris(dimethylamino) tin, i-butyl tris(dimethylamino) tin, n-butyltris(dimethylamino) tin, sec-butyl tris(dimethylamino) tin,i-propyl(tris)dimethylamino tin, n-propyl tris(diethylamino) tin, andanalogous alkyl(tris)(t-butoxy) tin compounds, including sec-hexyltris(t-butoxy) tin, t-hexyl tris(t-butoxy) tin, i-hexyl tris(t-butoxy)tin, n-hexyl tris(t-butoxy) tin, sec-pentyl tris(t-butoxy) tin, t-pentyltris(t-butoxy) tin, i-pentyl tris(t-butoxy) tin, n-pentyl tris(t-butoxy)tin, t-butyl tris(t-butoxy) tin, i-butyl tris(butoxy) tin, n-butyltris(butoxy) tin, sec-butyl tris(butoxy) tin,i-propyl(tris)dimethylamino tin, or n-propyl tris(butoxy) tin. In someembodiments, the organometallic precursors or organometallic compoundsare fluorinated. In some embodiments, the organometallic precursors orcompounds have a boiling point less than about 200° C.

In some embodiments, the first compound or first precursor includes oneor more unsaturated bonds that can be coordinated with a functionalgroup, such as a hydroxyl group, on the surface of the substrate or anintervening underlayer to improve adhesion of the photoresist layer tothe substrate or underlayer.

In some embodiments, the second precursor or second compound is at leastone of an amine, a borane, a phosphine, or water. In some embodiments,the amine has a formula N_(p)H_(n)X_(m), where 0≤n≤3, 0≤m≤3, n+m=3 whenp is 1, and n+m=4 when p is 2, and each X is independently a halogenselected from the group consisting of F, Cl, Br, and I. In someembodiments, the borane has a formula B_(p)H_(n)X_(m), where 0≤n≤3,0≤m≤3, n+m=3 when p is 1, and n+m=4 when p is 2, and each X isindependently a halogen selected from the group consisting of F, Cl, Br,and I. In some embodiments, the phosphine has a formula P_(p)H_(n)X_(m),where 0≤n≤3, 0≤m≤3, n+m=3, when p is 1, or n+m=4 when p is 2, and each Xis independently a halogen selected from the group consisting of F, Cl,Br, and I.

In some embodiments, the second precursor or compound is water, ammonia,or hydrazine. The reaction product of the water, ammonia, or hydrazineand the organometallic precursor or compound may form hydrogen bondsthat increase the boiling point of the reaction product and preventemission of the metal photoresist material, thereby preventing metalcontamination. The hydrogen bonds can also help prevent moisture effectsto the photoresist layer quality.

FIG. 9B shows a reaction metallic precursors undergo as a result ofexposure to actinic radiation in some embodiment As a result of exposureto the actinic radiation, ligand groups L are split off from themetallic core M⁺ of the metallic precursors, and two or more metallicprecursor cores bond with each other.

FIG. 9C shows examples of organometallic precursors according toembodiments of the disclosure. In FIG. 9C Bz is a benzene group.

In some embodiments, the operation S110 of depositing a photoresistcomposition is performed by a vapor phase deposition operation. In someembodiments, the vapor phase deposition operation includes atomic layerdeposition (ALD) or chemical vapor deposition (CVD). In someembodiments, the ALD includes plasma-enhanced atomic layer deposition(PE-ALD), and the CVD includes plasma-enhanced chemical vapor deposition(PE-CVD), metal-organic chemical vapor deposition (MO-CVD); atmosphericpressure chemical vapor deposition (AP-CVD), and low pressure chemicalvapor deposition (LP-CVD).

A resist layer deposition apparatus 200 according to some embodiments ofthe disclosure is shown in FIG. 10. In some embodiments, the depositionapparatus 200 is an ALD or CVD apparatus. The deposition apparatus 200includes a vacuum chamber 205. A substrate support stage 210 in thevacuum chamber 205 supports a substrate 10, such as silicon wafer. Insome embodiments, the substrate support stage 210 includes a heater. Afirst precursor or compound gas supply 220 and carrier/purge gas supply225 are connected to an inlet 230 in the chamber via a gas line 235, anda second precursor or compound gas supply 240 and carrier/purge gassupply 225 are connected to another inlet 230′ in the chamber viaanother gas line 235′ in some embodiments. The chamber is evacuated, andexcess reactants and reaction byproducts are removed by a vacuum pump245 via an outlet 250 and exhaust line 255. In some embodiments, theflow rate or pulses of precursor gases and carrier/purge gases,evacuation of excess reactants and reaction byproducts, pressure insidethe vacuum chamber 205, and temperature of the vacuum chamber 205 orwafer support stage 210 are controlled by a controller 260 configured tocontrol each of these parameters.

Depositing a photoresist layer includes combining the first compound orfirst precursor and the second compound or second precursor in a vaporstate to form the photoresist composition. In some embodiments, thefirst compound or first precursor and the second compound or secondprecursor of the photoresist composition are introduced into thedeposition chamber 205 (CVD chamber) at about the same time via theinlets 230, 230′. In some embodiments, the first compound or firstprecursor and second compound or second precursor are introduced intothe deposition chamber 205 (ALD chamber) in an alternating manner viathe inlets 230, 230′, i.e.—first one compound or precursor then a secondcompound or precursor, and then subsequently alternately repeating theintroduction of the one compound or precursor followed by the secondcompound or precursor.

In some embodiments, the deposition chamber temperature ranges fromabout 30° C. to about 400° C. during the deposition operation, andbetween about 50° C. to about 250° C. in other embodiments. In someembodiments, the pressure in the deposition chamber ranges from about 5mTorr to about 100 Torr during the deposition operation, and betweenabout 100 mTorr to about 10 Torr in other embodiments. In someembodiments, the plasma power is less than about 1000 W. In someembodiments, the plasma power ranges from about 100 W to about 900 W. Insome embodiments, the flow rate of the first compound or precursor andthe second compound or precursor ranges from about 100 sccm to about1000 sccm. In some embodiments, the ratio of the flow of theorganometallic compound precursor to the second compound or precursorranges from about 1:1 to about 1:5. At operating parameters outside theabove-recited ranges, unsatisfactory photoresist layers result in someembodiments. In some embodiments, the photoresist layer formation occursin a single chamber (a one-pot layer formation).

In a CVD process according to some embodiments of the disclosure, two ormore gas streams, in separate inlet paths 230, 235 and 230′, 235′, of anorganometallic precursor and a second precursor are introduced to thedeposition chamber 205 of a CVD apparatus, where they mix and react inthe gas phase, to form a reaction product. The streams are introducedusing separate injection inlets 230, 230′ or a dual-plenum showerhead insome embodiments. The deposition apparatus is configured so that thestreams of organometallic precursor and second precursor are mixed inthe chamber, allowing the organometallic precursor and second precursorto react to form a reaction product. Without limiting the mechanism,function, or utility of the disclosure, it is believed that the productfrom the vapor-phase reaction becomes heavier in molecular weight, andis then condensed or otherwise deposited onto the substrate 10.

In some embodiments, an ALD process is used to deposit the photoresistlayer. During ALD, a layer is grown on a substrate 10 by exposing thesurface of the substrate to alternate gaseous compounds (or precursors).In contrast to CVD, the precursors are introduced as a series ofsequential, non-overlapping pulses. In each of these pulses, theprecursor molecules react with the surface in a self-limiting way, sothat the reaction terminates once all the reactive sites on the surfaceare consumed. Consequently, the maximum amount of material deposited onthe surface after a single exposure to all of the precursors (aso-called ALD cycle) is determined by the nature of theprecursor-surface interaction.

In an embodiment of an ALD process, an organometallic precursor ispulsed to deliver the metal-containing precursor to the substrate 10surface in a first half reaction. In some embodiments, theorganometallic precursor reacts with a suitable underlying species (forexample OH or NH functionality on the surface of the substrate) to forma new self-saturating surface. Excess unused reactants and the reactionby-products are removed, by an evacuation-pump down using a vacuum pump245 and/or by a flowing an inert purge gas in some embodiments. Then, asecond precursor, such as ammonia (NH₃), is pulsed to the depositionchamber in some embodiments. The NH₃ reacts with the organometallicprecursor on the substrate to obtain a reaction product photoresist onthe substrate surface. The second precursor also forms self-saturatingbonds with the underlying reactive species to provide anotherself-limiting and saturating second half reaction. A second purge isperformed to remove unused reactants and the reaction by-products insome embodiments. Pulses of the first precursor and second precursor arealternated with intervening purge operations until a desired thicknessof the photoresist layer is achieved.

In some embodiments, the photoresist layer 15 is formed to a thicknessof about 5 nm to about 50 nm, and to a thickness of about 10 nm to about30 nm in other embodiments. A person of ordinary skill in the art willrecognize that additional ranges of thicknesses within the explicitranges above are contemplated and are within the present disclosure. Thethickness can be evaluated using non-contact methods of x-rayreflectivity and/or ellipsometry based on the optical properties of thephotoresist layers. In some embodiments, each photoresist layerthickness is relatively uniform to facilitate processing. In someembodiments, the variation in thickness of the deposited photoresistlayer varies by no more than ±25% from the average thickness, in otherembodiments each photoresist layer thickness varies by no more than ±10%from the average photoresist layer thickness. In some embodiments, suchas high uniformity depositions on larger substrates, the evaluation ofthe photoresist layer uniformity may be evaluated with a 1 centimeteredge exclusion, i.e., the layer uniformity is not evaluated for portionsof the coating within 1 centimeter of the edge. A person of ordinaryskill in the art will recognize that additional ranges within theexplicit ranges above are contemplated and are within the presentdisclosure.

In some embodiments, the first and second compounds or precursors aredelivered into the deposition chamber 205 with a carrier gas. Thecarrier gas, a purge gas, a deposition gas, or other process gas maycontain nitrogen, hydrogen, argon, neon, helium, or combinationsthereof.

In some embodiments, the organometallic compound includes tin (Sn),antimony (Sb), bismuth (Bi), indium (In), and/or tellurium (Te) as themetal component, however, the disclosure is not limited to these metals.In other embodiments, additional suitable metals include titanium (Ti),zirconium (Zr), hafnium (Hf), vanadium (V), cobalt (Co), molybdenum(Mo), tungsten (W), aluminum (Al), gallium (Ga), silicon (Si), germanium(Ge), phosphorus (P), arsenic (As), yttrium (Y), lanthanum (La), cerium(Ce), lutetium (Lu), or combinations thereof. The additional metals canbe as alternatives to or in addition to the Sn, Sb, Bi, In, and/or Te.

The particular metal used may significantly influence the absorption ofradiation. Therefore, the metal component can be selected based on thedesired radiation and absorption cross section. Tin, antimony, bismuth,tellurium, and indium provide strong absorption of extreme ultravioletlight at 13.5 nm. Hafnium provides good absorption of electron beam andextreme UV radiation. Metal compositions including titanium, vanadium,molybdenum, or tungsten have strong absorption at longer wavelengths, toprovide, for example, sensitivity to 248 nm wavelength ultravioletlight.

FIG. 11 shows a reaction the photoresist composition components undergoas a result of exposure to actinic radiation and heating according to anembodiment of the disclosure. FIG. 11 shows an exemplary chemicalstructure of the photoresist layer (PR) at various stages of thephotoresist patterning method according to embodiments of thedisclosure. As shown in FIG. 11, the photoresist composition includes anorganometallic compound, for example SnX₂R₂, and a second compound, forexample ammonia (NH₃). When the organometallic compound and the ammoniaare combined, the organometallic compound reacts with some of theammonia in the vapor phase to form a reaction product with amine groupsattached to the metal (Sn) of the organometallic compound. The aminegroups in the as deposited photoresist layer have hydrogen bonds thatcan substantially increase the boiling point of the depositedphotoresist layer and prevent the outgassing of metal-containingphotoresist material, thereby preventing contamination of the depositionchamber and semiconductor device processing equipment by the metal inthe metal-containing photoresist. Moreover, the hydrogen bonds of theamine groups can control the effect moisture has on photoresist layerquality.

In some embodiments, the photoresist composition is an organicpolymer-based composition in a solvent deposited by a spin-on coatingprocedure, followed by a first heating to remove the solvent.

When subsequently exposed to extreme ultraviolet radiation, theorganometallic compound absorbs the extreme ultraviolet radiation andone or more organic R groups are cleaved from the organometalliccompound to form an amino metallic compound in the radiation exposedareas. Then, when the post-exposure bake (PEB) performed, the aminometallic compounds crosslink through the amine groups in someembodiments, as shown in FIG. 11. In some embodiments, partialcrosslinking of the amino metallic compounds occurs as a result of theexposure to extreme ultraviolet radiation.

In some embodiments, the surface treatment operation S115 is an in-situoperation, where the surface treatment is performed in the sameprocessing chamber as the photoresist deposition operation S110. Inother embodiments, the surface treatment operation 115 is an ex-situoperation, where the surface treatment is performed in a differentprocessing chamber than the photoresist deposition operation S110. Insome embodiments, the surface treatment operation S115 includes changingthe surface of the photoresist layer from a hydrophilic surface to ahydrophobic surface. In some embodiments, the surface treatmentoperation S115 includes replacing end groups of ligands in thephotoresist layer with a non-polar organic group. In some embodiments,the non-polar organic groups include alkyl or aryl groups. In someembodiments, the surface treatment includes converting hydrophilic endgroups on ligands in the photoresist layer to hydrophobic end groups. Insome embodiments, polar or hydrophilic end groups on the ligands, likehydroxyl (—OH) end groups, are replaced by or converted to non-polar orhydrophobic end groups, like methyl groups (—CH₃) or phenyl groups(—C₆H₅). In some embodiments, the surface treatment includes reactingend groups of ligands in the photoresist layer, such as —OH groups, withammonia, a silane, a silylamine, an alkyl halide, an aryl halide, asilicon halide, an alkyl amine, an aryl amine, a carboxy alkyl, or acarboxy aryl.

In some embodiments, the —OH end groups on a ligand are reacted with ahalosilane (SiR_(y)X_(4-y)), where X is a halogen and R is the ligand.At least one of the halogen reacts with hydrogen and is removed, and theend group is converted to SiR_(y)X_(3-y)O. The ligand R is a non-polaralkyl group, and y is 1-3, in some embodiments. In some embodiments, thereaction temperature is about 20° C. to about 500° C.

FIG. 12A shows a surface treatment operation according to an embodimentof the disclosure. As shown in FIG. 12A, the ligands L in the metallicresist have hydrophilic end groups (—OH groups). A silylamine (R₃SiNH₂)is reacted with the hydrophilic end groups, converting the hydrophilicend groups to hydrophobic end groups (silylamino groups)

In some embodiments, the surface treated layer 20 a is removed byexposure to ultraviolet radiation, including EUV; thermal treatment;developer solution; or etching. In some embodiments, the surface treatedlayer 20 a is removed by heating the surface treated layer 20 a to atemperature ranging from about 50° C. to about 400° C. In someembodiments, the surface treated layer 20 a is removed by exposing thesurface treated layer 20 a to ultraviolet radiation having a wavelengthranging from about 10 nm to about 400 nm.

In other embodiments, the cap layer 20 b is a thin layer or includes aplurality of thin layers. In some embodiments, the cap layer 20 b isdeposited by a chemical vapor deposition (CVD) operation or an atomiclayer deposition (ALD) operation (S110). The cap layer 20 b may beformed by an in-situ operation or an ex-situ operation. In someembodiments, the cap layer 20 b is formed in the same chamber as the CVDor ALD resist layer formation operations, i.e.—an in situ operation. Insome embodiments, the cap layer 20 b is a dielectric layer. In someembodiments, the cap layer 20 b is made of a silicon oxide, a siliconnitride, a silicon carbide, SiOC, SiON, or multilayer combinationsthereof. In some embodiments, the silicon oxide, silicon nitride,silicon carbide, SiOC, SiON groups are substituted with one or morepolar or non-polar alkyl or aryl groups. In some embodiments, thesilicon oxide, silicon nitride, silicon carbide, SiOC, SiON groups aresubstituted with a tertiary alkyl or tertiary phenyl group. In someembodiments, the substituent is a tert-butyl group.

In some embodiments, the cap layer 20 b is a spin-coated layer, such asa hexamethyldisilazane (HMDS), a spin-on glass (SOG), apolymethylmethacrylate (PMMA), or a spin-on carbon (SOC). In suchembodiments, the cap layer 20 b is formed in a different chamber thanthe resist layer formation operations (i.e.—an ex-situ operation). Insome embodiments, the cap layer 20 b does not include photoresisttopcoat layers used in immersion lithography processes. In someembodiments, the cap layer 20 b does not include organic polymers orHMDS. In some embodiments, the thickness of the cap layer 20 b rangesfrom about 0.5 nm to about 20 nm. Cap layer 20 b thicknesses below thisrange may be insufficient to prevent moisture and oxygen absorption, andphotoresist outgassing; and thicknesses above this range may not provideany additional benefit, and may interfere with subsequent processing ofthe resist. In some embodiments, the cap layer is a monolayer.

FIG. 12B shows a cap layer formation operation according to anembodiment of the disclosure. As shown in FIG. 12B, the ligands L in themetallic resist have polar, hydrophilic end groups (—OH groups). Asilicon oxide substituted with polar or non-polar organic groups, suchas, Si(OR)₄, is deposited over the resist layer. The cap layer reactswith the polar groups (—OH groups) on the surface of the resist layer toform a non-polar, hydrophobic end group (—OR group) over the resistlayer. In some embodiments, R is alkyl or phenyl groups. The non-polar,hydrophobic end groups protect the resist layer 15 from ambient moistureby preventing the penetration of moisture through the cap layer 20 b.

In other embodiments, the cap layer 20 b is formed by direct depositionof silicon oxide, such as SiO₂ over the resist layer by CVD or ALD. TheSiO₂ thickness ranges from about 3 nm to about 20 nm. The SiO₂ cap layer20 b protects the resist layer 15 from directly contacting air.

In some embodiments, the cap layer 20 b is removed by exposure toultraviolet radiation, including EUV; thermal treatment; developersolution; or etching. The cap layer is selected so that it does notnegatively affect the absorption of the actinic radiation during theselective exposure of the photoresist layer. In some embodiments, thecap layer 20 b is removed by heating the cap layer to a temperatureranging from about 50° C. to about 400° C. In some embodiments, the caplayer 20 b is removed by exposing the cap layer 20 b to ultravioletradiation having a wavelength ranging from about 10 nm to about 400 nm.

In some embodiments, a layer to be patterned 60 is disposed over thesubstrate prior to forming the photoresist layer, as shown in FIG. 13.In some embodiments, the layer to be patterned 60 is a metallizationlayer or a dielectric layer, such as a passivation layer, disposed overa metallization layer. In embodiments where the layer to be patterned 60is a metallization layer, the layer to be patterned 60 is formed of aconductive material using metallization processes, and metal depositiontechniques, including chemical vapor deposition, atomic layerdeposition, and physical vapor deposition (sputtering). Likewise, if thelayer to be patterned 60 is a dielectric layer, the layer to bepatterned 60 is formed by dielectric layer formation techniques,including thermal oxidation, chemical vapor deposition, atomic layerdeposition, and physical vapor deposition.

Then the surface of the photoresist layer is treated to form a surfacetreated layer 20 a, as explained in reference to FIG. 4, or a cap layer20 b is formed over the photoresist layer 15, as shown in FIG. 14A or14B, respectively.

The photoresist layer 15 is subsequently selectively exposed to actinicradiation 45 to form exposed regions 50 and unexposed regions 52 in thephotoresist layer, as shown in FIGS. 15A. 15B, 15C, 15D and describedherein in relation to FIGS. 5A-5D. As explained herein the photoresistis a negative-tone photoresist in some embodiments.

As shown in FIGS. 16A, 16B, 16C, 16D, 16E, and 16F, the unexposedphotoresist regions 52 are developed, as explained herein in referenceto FIGS. 6A-6F to form a pattern of photoresist openings 55, as shown inFIG. 17.

Then as shown in FIG. 18, the pattern 55 in the photoresist layer 15 istransferred to the layer to be patterned 60 using an etching operationand the photoresist layer is removed, as explained with reference toFIG. 7 to form pattern 55″ in the layer to be patterned 60.

The novel photoresist layer surface treatment or cap layer formation andphotolithographic patterning methods according to the present disclosureprovide higher semiconductor device feature resolution and density athigher wafer exposure throughput with reduced defects in a higherefficiency process than conventional exposure techniques. Embodiments ofthe disclosure provide stable photoresist coated substrates that haveincreased Q-time (the amount of time a photoresist can remain on asubstrate or layer to be patterned before the photoresist is exposed toactinic radiation to form a latent pattern). Embodiments of thedisclosure prevent moisture and oxygen absorption of the resist layer,and prevent outgassing of the resist layer during subsequent processing.Embodiments of the disclosure prevent contamination of processingchambers, handling tools, and other wafers by metallic resist residues.Embodiments of the present disclosure provide photoresist films ofimproved stability.

An embodiment of the disclosure is a method of forming a pattern in aphotoresist layer, including forming a photoresist layer over asubstrate, and reducing moisture or oxygen absorption characteristics ofthe photoresist layer. The photoresist layer is selectively exposed toactinic radiation to form a latent pattern, and the latent pattern isdeveloped by applying a developer to the selectively exposed photoresistlayer to form a pattern. In an embodiment, the photoresist layerincludes a metal-containing photoresist composition. In an embodiment,the reducing moisture or oxygen absorption characteristics of thephotoresist layer comprises forming a cap layer over the photoresistlayer, wherein the cap layer is made of a silicon oxide, a siliconnitride, a silicon carbide, SiOC, SiON, or multilayer combinationsthereof. In an embodiment, the cap layer is a monolayer. In anembodiment, the cap layer is formed by chemical vapor deposition oratomic layer deposition. In an embodiment, the reducing moisture oroxygen absorption characteristics of the photoresist layer includesperforming a surface treatment to a surface of the photoresist layer. Inan embodiment, the surface treatment includes reacting end groups ofligands in the photoresist layer with ammonia, a silane, a silylamine,an alkyl halide, an aryl halide, a silicon halide, an alkyl amine,carboxy alkyls, or a carboxy aryl. In an embodiment, the surfacetreatment includes replacing end groups of ligands in the photoresistlayer with a non-polar organic group. In an embodiment, the surfacetreatment includes changing the surface of the photoresist layer from ahydrophilic surface to a hydrophobic surface. In an embodiment, thesurface treatment includes converting hydrophilic end groups on ligandsin the photoresist layer to hydrophobic end groups. In an embodiment,the actinic radiation is extreme ultraviolet radiation. In anembodiment, the method includes after selectively exposing thephotoresist layer to actinic radiation to form a latent pattern andbefore developing the latent pattern, post-exposure baking thephotoresist layer. In an embodiment, the post-exposure baking isperformed at a temperature ranging from 100° C. to 500° C. In anembodiment, the surface treatment comprises treating photoresist with aplasma or thermally treating the surface of the photoresist layer. In anembodiment, a surface treated portion of the photoresist layer isremoved by exposure to ultraviolet radiation, exposure to extremeultraviolet radiation, thermal treatment, developer solution, oretching. In an embodiment, the cap layer is formed by a chemical vapordeposition (CVD) operation or an atomic layer deposition (ALD)operation. In an embodiment, the cap layer is removed by exposure toultraviolet radiation, exposure to extreme ultraviolet radiation,thermal treatment, developer solution, or etching. In an embodiment, thecap layer is removed during the developing the latent pattern.

Another embodiment of the disclosure is a method of manufacturing asemiconductor device, including forming a photoresist layer over asubstrate by combining a first precursor and a second precursor in avapor state to form a photoresist material, and depositing thephotoresist material over the substrate. The moisture or oxygenabsorption characteristics of the photoresist layer is reduced. Thephotoresist layer is selectively exposed to actinic radiation to form alatent pattern in the photoresist layer. The latent pattern is developedby applying a developer to the selectively exposed photoresist layer toform a pattern in the photoresist layer, and the pattern in thephotoresist layer is extended into the substrate. In an embodiment, thefirst precursor is an organometallic having a formula: M_(a)R_(b)X_(c),where M is at least one of Sn, Bi, Sb, In, Te, Ti, Zr, Hf, V, Co, Mo, W,Al, Ga, Si, Ge, P, As, Y, La, Ce, or Lu; R is a substituted orunsubstituted alkyl, alkenyl, or carboxylate group; X is a halide orsulfonate group; and 1≤a≤2, b≥1, c≥1, and b+c≤5; and the secondprecursor is at least one of an amine, a borane, a phosphine, or water.In an embodiment, the photoresist material is deposited over thesubstrate by atomic layer deposition (ALD) or chemical vapor deposition(CVD). In an embodiment, the reducing moisture or oxygen absorptioncharacteristics of the photoresist layer includes changing a surface ofthe photoresist layer from a hydrophilic surface to a hydrophobicsurface. In an embodiment, the reducing the moisture or oxygenabsorption of the photoresist layer includes forming a cap layer made ofa silicon oxide, a silicon nitride, a silicon carbide, SiOC, SiON, ormultilayer combinations thereof. In an embodiment, the method includesremoving the cap layer or surface-treated portion of the photoresistlayer during the developing the latent pattern. In an embodiment, thereducing moisture or oxygen absorption characteristics of thephotoresist layer includes reacting end groups of ligands in thephotoresist layer with ammonia, a silane, a silylamine, an alkyl halide,an aryl halide, a silicon halide, an alkyl amine, a carboxy alkyl, or acarboxyl aryl. In an embodiment, the reducing moisture or oxygenabsorption characteristics of the photoresist layer includes replacingend groups of ligands in the photoresist layer with a non-polar organicgroup. In an embodiment, the reducing moisture or oxygen absorptioncharacteristics of the photoresist layer includes converting hydrophilicend groups on ligands in the photoresist layer to hydrophobic endgroups. In an embodiment, the cap layer is a monolayer.

Another embodiment of the disclosure is a method of manufacturing asemiconductor device, including depositing a photoresist compositionincluding a first organometallic compound and a second compound over asubstrate surface via atomic layer deposition (ALD) or chemical vapordeposition (CVD) to form a photoresist layer. Moisture or oxygenabsorption characteristics of the photoresist layer are reduced. Thephotoresist layer is selectively exposed to actinic radiation to form alatent pattern. The latent pattern is developed by applying a developerto the selectively exposed photoresist layer to form a pattern exposinga portion of the substrate surface. A portion of the substrate surfaceexposed by the developing is removed. In an embodiment, the removing aportion of the substrate surface by the developing includes etching thesubstrate surface. In an embodiment, the method includes afterselectively exposing the photoresist layer to form a latent pattern,heating the photoresist layer at a temperature ranging from 100° C. to500° C. In an embodiment, the reducing moisture or oxygen absorptioncharacteristics of the photoresist layer includes reacting end groups ofligands in the photoresist layer with ammonia, a silane, an alkylhalide, a silicon halide, an amino alkyls, or carboxyl alkyls. In anembodiment, the reducing the moisture or oxygen absorption of thephotoresist layer includes forming a cap layer made of a silicon oxide,a silicon nitride, a silicon carbide, SiOC, SiON, or multilayercombinations thereof. In an embodiment, the reducing moisture or oxygenabsorption characteristics of the photoresist layer includes replacingend groups of ligands in the photoresist layer with a non-polar organicgroup. In an embodiment, the reducing moisture or oxygen absorptioncharacteristics of the photoresist layer includes changing a surface ofthe photoresist layer from a hydrophilic surface to a hydrophobicsurface. In an embodiment, the reducing moisture or oxygen absorptioncharacteristics of the photoresist layer includes converting hydrophilicend groups on ligands in the photoresist layer to hydrophobic endgroups. In an embodiment, the cap layer is a monolayer. In anembodiment, the actinic radiation is extreme ultraviolet radiation.

Another embodiment of the disclosure is a method including forming aresist layer over a substrate, and surface treating a surface of theresist layer or forming a cap layer made of a silicon oxide, a siliconnitride, a silicon carbide, SiOC, SiON, or multilayer combinationsthereof over the resist layer. The resist layer is patternwisecrosslinked, and a portion of the resist layer not crosslinked isremoved during the patternwise crosslinking to form a pattern in theresist layer. In an embodiment, the method includes heating the resistlayer after the patternwise crosslinking and before the removing aportion of the resist layer not crosslinked. In an embodiment, theresist layer is heated at a temperature ranging from 100° C. to 500° C.during the heating the resist layer. In an embodiment, the removing aportion of the resist layer includes applying a developer to thepatternwise crosslinked resist layer. In an embodiment, the removing aportion of the resist layer includes applying a plasma to thepatternwise crosslinked resist layer. In an embodiment, asurface-treated portion of the resist layer or the cap layer is removedafter the patternwise crosslinking the resist layer and before theremoving a portion of the resist layer. In an embodiment, a surfacetreated portion of the resist layer or the cap layer is removed byexposure to ultraviolet radiation, exposure to extreme ultravioletradiation, a thermal treatment, a developer solution, or etching. In anembodiment, the resist layer is formed over the substrate by combining afirst precursor and a second precursor in a vapor state to form a resistmaterial, wherein the first precursor is an organometallic having aformula: M_(a)R_(b)X_(c), where M is at least one of Sn, Bi, Sb, In, Te,Ti, Zr, Hf, V, Co, Mo, W, Al, Ga, Si, Ge, P, As, Y, La, Ce, or Lu; R isa substituted or unsubstituted alkyl, alkenyl, or carboxylate group; Xis a halide or sulfonate group; and 1≤a≤2, b≥1, c≥1, and b+c≤5; and thesecond precursor is at least one of an amine, a borane, a phosphine, orwater. In an embodiment, the resist layer is deposited over thesubstrate by atomic layer deposition (ALD) or chemical vapor deposition(CVD).

Another embodiment of the disclosure is a method of patterning a resistlayer, including depositing a resist layer over a substrate surface byatomic layer deposition (ALD) or chemical vapor deposition (CVD). Theresist layer includes a reaction product of an organometallic compoundand at least one of an amine, a borane, a phosphine, and water. Asurface of the resist layer is surface treated or a cap layer is formedover the resist layer. After treating the surface of the resist layer orforming the cap layer, the resist layer is patternwise crosslinked toform a latent pattern in the resist layer. The latent pattern isdeveloped by applying a developer to the patternwise crosslinked resistlayer to form a pattern exposing a portion of the substrate surface. Inan embodiment, the method includes a first heating of the resist layerbefore the patternwise crosslinking. In an embodiment, the surfacetreating or the forming the cap layer is performed before the firstheating. In an embodiment, the surface treating or the forming the caplayer is performed after the first heating. In an embodiment, the methodincludes a second heating of the resist layer after the patternwisecrosslinking. In an embodiment, the second heating of the resist layeris performed at temperature ranging from 100° C. to 500° C. In anembodiment, the method includes removing an exposed portion of thesubstrate surface after the developing. In an embodiment, thepatternwise crosslinking the resist layer includes patternwise exposingthe resist layer to extreme ultraviolet radiation.

Another embodiment of the disclosure is a method of manufacturing asemiconductor device, including depositing a reaction product of a vaporphase organometallic compound and a second vapor phase compound over asubstrate to form a resist layer over the substrate. The organometalliccompound has a formula: M_(a)R_(b)X_(c), where M is at least one of Sn,Bi, Sb, In, Te, Ti, Zr, Hf, V, Co, Mo, W, Al, Ga, Si, Ge, P, As, Y, La,Ce, or Lu; R is a substituted or unsubstituted alkyl, alkenyl, orcarboxylate group; X is a halide or sulfonate group; and 1≤a≤2, b≥1,c≥1, and b+c≤5; and the second vapor phase compound is at least one ofan amine, a borane, a phosphine, or water. A surface of the resist layeris surface treated or a cap layer is formed over the resist layer. Theresist layer is patternwise crosslinked to form a latent pattern in theresist layer. After patternwise crosslinking the resist layer, a surfacetreated portion of the resist layer or the cap layer is removed. Thelatent pattern is developed by applying a developer to the patternwisecrosslinked resist layer to form a pattern exposing a surface portion ofthe substrate. In an embodiment, the surface treated portion of theresist layer or the cap layer is removed during the developing thelatent pattern. In an embodiment, the patternwise crosslinking theresist layer includes patternwise exposing the resist layer to extremeultraviolet radiation through a surface treated portion of the resistlayer or the cap layer, and heating the patternwise exposed resistlayer. In an embodiment, the patternwise exposed resist layer is heatedat a temperature ranging from 100° C. to 500° C. In an embodiment, thecap layer is formed, and the cap layer is not a photosensitive layer. Inan embodiment, the method includes removing a portion of the substrateexposed by the developing. In an embodiment, the method includes heatingthe resist layer at temperature ranging from 40° C. to 150° C. beforepatternwise crosslinking the resist layer. In an embodiment, the surfacetreating includes reacting end groups of ligands in the resist layerwith ammonia, a silane, a silylamine, an alkyl halide, an aryl halide, asilicon halide, an alkyl amine, a carboxy alkyl, or a carboxy aryl. Inan embodiment, the surface treating includes replacing end groups ofligands in the resist layer with a non-polar organic group. In anembodiment, the surface treating includes changing the surface of theresist layer from a hydrophilic surface to a hydrophobic surface. In anembodiment, the surface treating includes converting hydrophilic endgroups on ligands in the resist layer to hydrophobic end groups. In anembodiment, the cap layer is a monolayer. In an embodiment, the caplayer is made of a silicon oxide, a silicon nitride, a silicon carbide,SiOC, SiON, or multilayer combinations thereof.

Another embodiment of the disclosure is a method of patterning aphotoresist layer, including depositing a photoresist layer over asubstrate by a vapor phase deposition operation. The photoresist layerincludes a reaction product of an organometallic compound and a secondcompound, wherein the second compound is at least one of an amine, aborane, a phosphine, or water. A cap layer is formed over thephotoresist layer, wherein the cap layer is made of a silicon oxide, asilicon nitride, a silicon carbide, SiOC, SiON, or multilayercombinations thereof. The photoresist layer is selectively exposed toactinic radiation through the cap layer to form a latent pattern in thephotoresist layer. The cap layer is removed, and portions of thephotoresist layer not exposed to the actinic radiation is removed toform a pattern of remaining portions of the photoresist layer that wereexposed to the actinic radiation during the selectively exposing thephotoresist layer. In an embodiment, the method includes removingportions of the substrate exposed by the removing portions of thephotoresist layer. In an embodiment, the removing portions of thesubstrate includes dry etching the substrate. In an embodiment, theremoving the portions of the photoresist layer includes applying aplasma to the photoresist layer. In an embodiment, the vapor phasedeposition operation includes atomic layer deposition or chemical vapordeposition. In an embodiment, the cap layer is formed by atomic layerdeposition of chemical vapor deposition. In an embodiment, the methodincludes heating the photoresist layer at temperature ranging from 40°C. to 150° C. before selectively exposing the photoresist layer toactinic radiation. In an embodiment, the cap layer is formed before theheating the photoresist layer at a temperature ranging from 40° C. to150° C. In an embodiment, the cap layer is formed after heating thephotoresist layer at a temperature ranging from 40° C. to 150° C. In anembodiment, the cap layer is removed during the removing portions of thephotoresist layer not exposed to the actinic radiation. In anembodiment, the method includes heating the cap layer and thephotoresist layer at a temperature ranging from 100° C. to 500° C. afterselectively exposing the photoresist layer to actinic radiation.

The foregoing outlines features of several embodiments or examples sothat those skilled in the art may better understand the aspects of thepresent disclosure. Those skilled in the art should appreciate that theymay readily use the present disclosure as a basis for designing ormodifying other processes and structures for carrying out the samepurposes and/or achieving the same advantages of the embodiments orexamples introduced herein. Those skilled in the art should also realizethat such equivalent constructions do not depart from the spirit andscope of the present disclosure, and that they may make various changes,substitutions, and alterations herein without departing from the spiritand scope of the present disclosure.

What is claimed is:
 1. A method of forming a pattern in a photoresistlayer, comprising: forming a photoresist layer over a substrate;reducing moisture or oxygen absorption characteristics of thephotoresist layer; selectively exposing the photoresist layer to actinicradiation to form a latent pattern; and developing the latent pattern byapplying a developer to the selectively exposed photoresist layer toform a pattern.
 2. The method according to claim 1, wherein thephotoresist layer comprises a metal-containing photoresist composition.3. The method according to claim 2, wherein the reducing moisture oroxygen absorption characteristics of the photoresist layer comprisesforming a cap layer over the photoresist layer, wherein the cap layer ismade of a silicon oxide, a silicon nitride, a silicon carbide, SiOC,SiON, or multilayer combinations thereof.
 4. The method according toclaim 3, wherein the cap layer is a monolayer.
 5. The method accordingto claim 3, wherein the cap layer is formed by chemical vapor depositionor atomic layer deposition.
 6. The method according to claim 2, whereinthe reducing moisture or oxygen absorption characteristics of thephotoresist layer comprises performing a surface treatment to a surfaceof the photoresist layer.
 7. The method according to claim 6, whereinthe surface treatment comprises reacting end groups of ligands in thephotoresist layer with ammonia, a silane, an alkyl halide, a siliconhalide, an amino alkyls, or carboxyl alkyls.
 8. The method according toclaim 6, wherein the surface treatment comprises replacing end groups ofligands in the photoresist layer with a non-polar organic group.
 9. Themethod according to claim 6, wherein the surface treatment compriseschanging the surface of the photoresist layer from a hydrophilic surfaceto a hydrophobic surface.
 10. The method according to claim 6, whereinthe surface treatment comprises converting hydrophilic end groups onligands in the photoresist layer to hydrophobic end groups.
 11. A methodof manufacturing a semiconductor device, comprising: forming aphotoresist layer over a substrate, comprising: combining a firstprecursor and a second precursor in a vapor state to form a photoresistmaterial, and depositing the photoresist material over the substrate;reducing moisture or oxygen absorption characteristics of thephotoresist layer; selectively exposing the photoresist layer to actinicradiation to form a latent pattern in the photoresist layer; developingthe latent pattern by applying a developer to the selectively exposedphotoresist layer to form a pattern in the photoresist layer; andextending the pattern in the photoresist layer into the substrate. 12.The method according to claim 11, wherein the first precursor is anorganometallic having a formula:M_(a)R_(b)X_(c) where M is at least one of Sn, Bi, Sb, In, Te, Ti, Zr,Hf, V, Co, Mo, W, Al, Ga, Si, Ge, P, As, Y, La, Ce, or Lu, R is asubstituted or unsubstituted alkyl, alkenyl, or carboxylate group, X isa halide or sulfonate group, and 1≤a≤2, b≥1, c≥1, and b+c≤5; and thesecond precursor is at least one of an amine, a borane, a phosphine, orwater.
 13. The method according to claim 11, wherein the photoresistmaterial is deposited over the substrate by atomic layer deposition(ALD) or chemical vapor deposition (CVD).
 14. The method according toclaim 11, wherein the reducing moisture or oxygen absorptioncharacteristics of the photoresist layer comprises changing a surface ofthe photoresist layer from a hydrophilic surface to a hydrophobicsurface.
 15. The method according to claim 11, wherein the reducing themoisture or oxygen absorption of the photoresist layer comprises forminga cap layer made of a silicon oxide, a silicon nitride, a siliconcarbide, SiOC, SiON, or multilayer combinations thereof.
 16. A method ofmanufacturing a semiconductor device, comprising: depositing aphotoresist composition comprising a first organometallic compound and asecond compound over a substrate surface via atomic layer deposition(ALD) or chemical vapor deposition (CVD) to form a photoresist layer;reducing moisture or oxygen absorption characteristics of thephotoresist layer; selectively exposing the photoresist layer to actinicradiation to form a latent pattern; developing the latent pattern byapplying a developer to the selectively exposed photoresist layer toform a pattern exposing a portion of the substrate surface; and removinga portion of the substrate surface exposed by the developing.
 17. Themethod according to claim 16, wherein the removing a portion of thesubstrate surface by the developing includes etching the substratesurface.
 18. The method according to claim 16, further comprising afterselectively exposing the photoresist layer to form a latent pattern,heating the photoresist layer at a temperature ranging from 100° C. to500° C.
 19. The method according to claim 16, wherein the reducingmoisture or oxygen absorption characteristics of the photoresist layercomprises reacting end groups of ligands in the photoresist layer withammonia, a silane, a silylamine, an alkyl halide, an aryl halide, asilicon halide, an alkyl amine, a carboxy alkyl, or a carboxy aryl. 20.The method according to claim 16, wherein the reducing the moisture oroxygen absorption of the photoresist layer comprises forming a cap layermade of a silicon oxide, a silicon nitride, a silicon carbide, SiOC,SiON, or multilayer combinations thereof.